<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<link rel="stylesheet" href="../common.css">
<style>
  body {
    background: #010d19;
  }

  .box {
    width: 100px;
    height: 200px;
    background: rgba(20, 97, 125, 0.16);
    box-shadow: 4px 2px 4px 0px rgba(0, 0, 0, 0.2);
    backdrop-filter: blur(4px);
    --border-radius: 50% 50% 50% 50% / 30% 30% 70% 70% ;
    --border-width: 2px;
    --border-color: linear-gradient(271deg, rgba(151, 151, 151, 0.3), rgba(131, 150, 162, 1), rgba(151, 151, 151, 0.3));
    border-radius: var(--border-radius);
  }

  .box::after {
    content: "";
    position: absolute;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    padding: var(--border-width);
    border-radius: var(--border-radius);
    background: var(--border-color);
    --mask-bg: linear-gradient(red, red);
    --m-o: content-box, padding-box;
    -webkit-mask-image: var(--mask-bg), var(--mask-bg);
    -webkit-mask-origin: var(--m-o);
    -webkit-mask-clip: var(--m-o);
    mask-composite: exclude;
    -webkit-mask-composite: destination-out;
  }
</style>

<body>
  <div class="box"></div>
</body>
<script></script>

</html>